Pollution water Water pollution is a phenomenon that changes the properties of water, detrimental to the water environment, largely caused by various human activities. Clean water does not contain contaminants, pathogenic bacteria and chemicals affecting human health. The cleanest water is distilled water in which the composition is just H2O . In addition, clean water is also regulated on the limited composition of some ions, some heavy metal ions, and some waste at concentrations below the allowable level of the World Health Organization. Contaminated water often contains organic wastes, pathogenic microorganisms, phytonutrients, synthetic organic chemicals, inorganic chemicals, radioactive substances, chemical toxins, ... 3. Pollution of the soil environment Soil pollution is all phenomena, the processes that pollute the soil, change the physical and chemical properties of the soil due to pollutants, leading to a decrease in soil fertility. Clean soil does not contain pollutants, some chemicals, if any, only reach the concentration below the specified level. Polluted soil contains a number of toxins, substances harmful to plants in excess of the prescribed concentration. For example: The concentration of pesticides, chemical fertilizers, heavy metals exceeds the regulations of the World Health Organization. Source of environmental pollution due to natural or man-made. Chemical production is one of the sources of environmental pollution caused by waste gas, solid waste, and wastewater which are toxic to humans and organisms. The harmful effects of polluted environment (air, soil, water) cause deterioration of human health, change the global climate, destroy some kinds of organisms, ... For example ozone, the greenhouse effect, acid rain,… are the result of environmental pollution.